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Re: [SeattleRobotics] sonar, etc.

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  • Michael Donnellan
    Higher frequencies may work well for close range avoidance behavior, but I need something for much greater depth and distance (100 - 500 meters). Also, some
    Message 1 of 22 , Nov 3, 2005
      Higher frequencies may work well for close range avoidance behavior, but I
      need something for much greater depth and distance (100 - 500 meters). Also,
      some frequencies that work in air or fresh water are seriously disrupted in
      sea water.



      On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:

      > That sound about right. NDT transducers are made to
      > find flaws in manufactured parts. The frequency sets
      > the size of flaw that will reflect sound back.
      >
      > --- "tbrenke@..." <tbrenke@...> wrote:
      >
      >> Mhz will not go far in water.
      >> 1.2Mhz is good for only about 20'
      >> (at best)
      >>
      >> Tony Brenke
      >> WESMAR
      >> (sonar maker)
      >>
      >>
      >>
      >>
      >> Charles Holzschuh wrote:
      >>
      >>> Try a non-destructive testing supplier. I don't
      >> know
      >>> any names. But, they have tons of underwater
      >>> transducers some focused some not. I beleive most
      >> are
      >>> in the MHz range.
      >>>
      >>> --- Jon Hylands <jon@...> wrote:
      >>>
      >>>
      >>>
      >>>> On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
      >>>> <m.w.donnellan@...> wrote:
      >>>>
      >>>>
      >>>>
      >>>>> I've done some work with land based sonar
      >>>>>
      >>>>>
      >>>> avoidance behavior...but I've moved on to wetter
      >>>>
      >>>>
      >>>>> climes. I'm wondering if anyone has used sonar on
      >>>>>
      >>>>>
      >>>> underwater autonomous applications and
      >>>>
      >>>>
      >>>>> if so, could recommend a good transducer (maybe
      >> in
      >>>>>
      >>>>>
      >>>> the 200 kHz range)?
      >>>>
      >>>> Mike,
      >>>>
      >>>> I got this word document from a guy a long time
      >> ago
      >>>> - he built a very
      >>>> simple AUV using a cheap R/C sub, and put a simple
      >>>> sonar on it, which he
      >>>> describes within.
      >>>>
      >>>> http://www.huv.com/maus2.zip
      >>>>
      >>>> Let me know if this works for you, or what you
      >> come
      >>>> up with - I'm obviously
      >>>> very interested in AUVs as well.
      >>>>
      >>>> Later,
      >>>> Jon
      >>>>
      >>>>
      >>>>
      >>>>
      >>
      >> --------------------------------------------------------------
      >>>
      >>>
      >>>> Jon Hylands Jon@...
      >>>> http://www.huv.com/jon
      >>>>
      >>>> Project: Micro Seeker (Micro Autonomous
      >> Underwater
      >>>> Vehicle)
      >>>> http://www.huv.com
      >>>>
      >>>>
      >>>> Visit the SRS Website at
      >>>> http://www.seattlerobotics.org
      >>>> Yahoo! Groups Links
      >>>>
      >>>>
      >>>> SeattleRobotics-unsubscribe@yahoogroups.com
      >>>>
      >>>>
      >>>>
      >>>>
      >>>>
      >>>>
      >>>>
      >>>
      >>>
      >>>
      >>>
      >>> __________________________________
      >>> Yahoo! FareChase: Search multiple travel sites in
      >> one click.
      >>> http://farechase.yahoo.com
      >>>
      >>>
      >>> Visit the SRS Website at
      >> http://www.seattlerobotics.org
      >>> Yahoo! Groups Links
      >>>
      >>>
      >>>
      >>>
      >>>
      >>>
      >>>
      >>>
      >>>
      >>>
      >>
      >>
      >> Visit the SRS Website at
      >> http://www.seattlerobotics.org
      >> Yahoo! Groups Links
      >>
      >>
      >> SeattleRobotics-unsubscribe@yahoogroups.com
      >>
      >>
      >>
      >>
      >>
      >>
      >
      >
      >
      >
      >
      > __________________________________
      > Yahoo! Mail - PC Magazine Editors' Choice 2005
      > http://mail.yahoo.com
      >
      >
      > Visit the SRS Website at http://www.seattlerobotics.org
      > Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
    • Tom Capon
      then there s the whole thing about disrupting sea *life* with various frequencies/magnitudes of sonar. There was recently some controversy over here on the
      Message 2 of 22 , Nov 3, 2005
        then there's the whole thing about disrupting sea *life* with various
        frequencies/magnitudes of sonar. There was recently some controversy over
        here on the east coast about a Navy training ground that had high-powered
        radar concentrated in one place damaging whales' ears and the like.

        On 11/3/05, Michael Donnellan <m.w.donnellan@...> wrote:
        >
        > Higher frequencies may work well for close range avoidance behavior, but I
        > need something for much greater depth and distance (100 - 500 meters).
        > Also,
        > some frequencies that work in air or fresh water are seriously disrupted
        > in
        > sea water.
        >
        >
        >
        > On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
        >
        > > That sound about right. NDT transducers are made to
        > > find flaws in manufactured parts. The frequency sets
        > > the size of flaw that will reflect sound back.
        > >
        > > --- "tbrenke@..." <tbrenke@...> wrote:
        > >
        > >> Mhz will not go far in water.
        > >> 1.2Mhz is good for only about 20'
        > >> (at best)
        > >>
        > >> Tony Brenke
        > >> WESMAR
        > >> (sonar maker)
        > >>
        > >>
        > >>
        > >>
        > >> Charles Holzschuh wrote:
        > >>
        > >>> Try a non-destructive testing supplier. I don't
        > >> know
        > >>> any names. But, they have tons of underwater
        > >>> transducers some focused some not. I beleive most
        > >> are
        > >>> in the MHz range.
        > >>>
        > >>> --- Jon Hylands <jon@...> wrote:
        > >>>
        > >>>
        > >>>
        > >>>> On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
        > >>>> <m.w.donnellan@...> wrote:
        > >>>>
        > >>>>
        > >>>>
        > >>>>> I've done some work with land based sonar
        > >>>>>
        > >>>>>
        > >>>> avoidance behavior...but I've moved on to wetter
        > >>>>
        > >>>>
        > >>>>> climes. I'm wondering if anyone has used sonar on
        > >>>>>
        > >>>>>
        > >>>> underwater autonomous applications and
        > >>>>
        > >>>>
        > >>>>> if so, could recommend a good transducer (maybe
        > >> in
        > >>>>>
        > >>>>>
        > >>>> the 200 kHz range)?
        > >>>>
        > >>>> Mike,
        > >>>>
        > >>>> I got this word document from a guy a long time
        > >> ago
        > >>>> - he built a very
        > >>>> simple AUV using a cheap R/C sub, and put a simple
        > >>>> sonar on it, which he
        > >>>> describes within.
        > >>>>
        > >>>> http://www.huv.com/maus2.zip
        > >>>>
        > >>>> Let me know if this works for you, or what you
        > >> come
        > >>>> up with - I'm obviously
        > >>>> very interested in AUVs as well.
        > >>>>
        > >>>> Later,
        > >>>> Jon
        > >>>>
        > >>>>
        > >>>>
        > >>>>
        > >>
        > >> --------------------------------------------------------------
        > >>>
        > >>>
        > >>>> Jon Hylands Jon@...
        > >>>> http://www.huv.com/jon
        > >>>>
        > >>>> Project: Micro Seeker (Micro Autonomous
        > >> Underwater
        > >>>> Vehicle)
        > >>>> http://www.huv.com
        > >>>>
        > >>>>
        > >>>> Visit the SRS Website at
        > >>>> http://www.seattlerobotics.org
        > >>>> Yahoo! Groups Links
        > >>>>
        > >>>>
        > >>>> SeattleRobotics-unsubscribe@yahoogroups.com
        > >>>>
        > >>>>
        > >>>>
        > >>>>
        > >>>>
        > >>>>
        > >>>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>> __________________________________
        > >>> Yahoo! FareChase: Search multiple travel sites in
        > >> one click.
        > >>> http://farechase.yahoo.com
        > >>>
        > >>>
        > >>> Visit the SRS Website at
        > >> http://www.seattlerobotics.org
        > >>> Yahoo! Groups Links
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>>
        > >>
        > >>
        > >> Visit the SRS Website at
        > >> http://www.seattlerobotics.org
        > >> Yahoo! Groups Links
        > >>
        > >>
        > >> SeattleRobotics-unsubscribe@yahoogroups.com
        > >>
        > >>
        > >>
        > >>
        > >>
        > >>
        > >
        > >
        > >
        > >
        > >
        > > __________________________________
        > > Yahoo! Mail - PC Magazine Editors' Choice 2005
        > > http://mail.yahoo.com
        > >
        > >
        > > Visit the SRS Website at http://www.seattlerobotics.org
        > > Yahoo! Groups Links
        > >
        > >
        > >
        > >
        > >
        > >
        >
        >
        >
        >
        > Visit the SRS Website at http://www.seattlerobotics.org
        > Yahoo! Groups Links
        >
        >
        >
        >
        >
        >
        >


        [Non-text portions of this message have been removed]
      • Michael Donnellan
        Very true...we ve had problems with that here in the Pacific Northwest particularly with Orcas.
        Message 3 of 22 , Nov 3, 2005
          Very true...we've had problems with that here in the Pacific Northwest
          particularly with Orcas.



          On 11/3/05 8:56 PM, "Tom Capon" <robot256@...> wrote:

          > then there's the whole thing about disrupting sea *life* with various
          > frequencies/magnitudes of sonar. There was recently some controversy over
          > here on the east coast about a Navy training ground that had high-powered
          > radar concentrated in one place damaging whales' ears and the like.
          >
          > On 11/3/05, Michael Donnellan <m.w.donnellan@...> wrote:
          >>
          >> Higher frequencies may work well for close range avoidance behavior, but I
          >> need something for much greater depth and distance (100 - 500 meters).
          >> Also,
          >> some frequencies that work in air or fresh water are seriously disrupted
          >> in
          >> sea water.
          >>
          >>
          >>
          >> On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
          >>
          >>> That sound about right. NDT transducers are made to
          >>> find flaws in manufactured parts. The frequency sets
          >>> the size of flaw that will reflect sound back.
          >>>
          >>> --- "tbrenke@..." <tbrenke@...> wrote:
          >>>
          >>>> Mhz will not go far in water.
          >>>> 1.2Mhz is good for only about 20'
          >>>> (at best)
          >>>>
          >>>> Tony Brenke
          >>>> WESMAR
          >>>> (sonar maker)
          >>>>
          >>>>
          >>>>
          >>>>
          >>>> Charles Holzschuh wrote:
          >>>>
          >>>>> Try a non-destructive testing supplier. I don't
          >>>> know
          >>>>> any names. But, they have tons of underwater
          >>>>> transducers some focused some not. I beleive most
          >>>> are
          >>>>> in the MHz range.
          >>>>>
          >>>>> --- Jon Hylands <jon@...> wrote:
          >>>>>
          >>>>>
          >>>>>
          >>>>>> On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
          >>>>>> <m.w.donnellan@...> wrote:
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>> I've done some work with land based sonar
          >>>>>>>
          >>>>>>>
          >>>>>> avoidance behavior...but I've moved on to wetter
          >>>>>>
          >>>>>>
          >>>>>>> climes. I'm wondering if anyone has used sonar on
          >>>>>>>
          >>>>>>>
          >>>>>> underwater autonomous applications and
          >>>>>>
          >>>>>>
          >>>>>>> if so, could recommend a good transducer (maybe
          >>>> in
          >>>>>>>
          >>>>>>>
          >>>>>> the 200 kHz range)?
          >>>>>>
          >>>>>> Mike,
          >>>>>>
          >>>>>> I got this word document from a guy a long time
          >>>> ago
          >>>>>> - he built a very
          >>>>>> simple AUV using a cheap R/C sub, and put a simple
          >>>>>> sonar on it, which he
          >>>>>> describes within.
          >>>>>>
          >>>>>> http://www.huv.com/maus2.zip
          >>>>>>
          >>>>>> Let me know if this works for you, or what you
          >>>> come
          >>>>>> up with - I'm obviously
          >>>>>> very interested in AUVs as well.
          >>>>>>
          >>>>>> Later,
          >>>>>> Jon
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>
          >>>> --------------------------------------------------------------
          >>>>>
          >>>>>
          >>>>>> Jon Hylands Jon@...
          >>>>>> http://www.huv.com/jon
          >>>>>>
          >>>>>> Project: Micro Seeker (Micro Autonomous
          >>>> Underwater
          >>>>>> Vehicle)
          >>>>>> http://www.huv.com
          >>>>>>
          >>>>>>
          >>>>>> Visit the SRS Website at
          >>>>>> http://www.seattlerobotics.org
          >>>>>> Yahoo! Groups Links
          >>>>>>
          >>>>>>
          >>>>>> SeattleRobotics-unsubscribe@yahoogroups.com
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>> __________________________________
          >>>>> Yahoo! FareChase: Search multiple travel sites in
          >>>> one click.
          >>>>> http://farechase.yahoo.com
          >>>>>
          >>>>>
          >>>>> Visit the SRS Website at
          >>>> http://www.seattlerobotics.org
          >>>>> Yahoo! Groups Links
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>>
          >>>>
          >>>>
          >>>> Visit the SRS Website at
          >>>> http://www.seattlerobotics.org
          >>>> Yahoo! Groups Links
          >>>>
          >>>>
          >>>> SeattleRobotics-unsubscribe@yahoogroups.com
          >>>>
          >>>>
          >>>>
          >>>>
          >>>>
          >>>>
          >>>
          >>>
          >>>
          >>>
          >>>
          >>> __________________________________
          >>> Yahoo! Mail - PC Magazine Editors' Choice 2005
          >>> http://mail.yahoo.com
          >>>
          >>>
          >>> Visit the SRS Website at http://www.seattlerobotics.org
          >>> Yahoo! Groups Links
          >>>
          >>>
          >>>
          >>>
          >>>
          >>>
          >>
          >>
          >>
          >>
          >> Visit the SRS Website at http://www.seattlerobotics.org
          >> Yahoo! Groups Links
          >>
          >>
          >>
          >>
          >>
          >>
          >>
          >
          >
          > [Non-text portions of this message have been removed]
          >
          >
          >
          > Visit the SRS Website at http://www.seattlerobotics.org
          > Yahoo! Groups Links
          >
          >
          >
          >
          >
          >
        • tbrenke@verizon.net
          seawater common sonar freqs by distance long range 50Khz 60Khz 110Khz 120Khz 200Khz 300Khz abt 700 feet max (in fresh water) 455Khz you are looking for
          Message 4 of 22 , Nov 4, 2005
            seawater common sonar freqs by distance
            long range
            50Khz
            60Khz
            110Khz
            120Khz
            200Khz
            300Khz abt 700 feet max (in fresh water)
            455Khz

            you are looking for 60-110Khz sonar.
            another factor with the freq is the size of the target you can see.
            a 300Khz will see detals that a 110Khz and 60Khz will not.


            Michael Donnellan wrote:

            >Higher frequencies may work well for close range avoidance behavior, but I
            >need something for much greater depth and distance (100 - 500 meters). Also,
            >some frequencies that work in air or fresh water are seriously disrupted in
            >sea water.
            >
            >
            >
            >On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
            >
            >
            >
            >>That sound about right. NDT transducers are made to
            >>find flaws in manufactured parts. The frequency sets
            >>the size of flaw that will reflect sound back.
            >>
            >>--- "tbrenke@..." <tbrenke@...> wrote:
            >>
            >>
            >>
            >>>Mhz will not go far in water.
            >>>1.2Mhz is good for only about 20'
            >>>(at best)
            >>>
            >>>Tony Brenke
            >>>WESMAR
            >>>(sonar maker)
            >>>
            >>>
            >>>
            >>>
            >>>Charles Holzschuh wrote:
            >>>
            >>>
            >>>
            >>>>Try a non-destructive testing supplier. I don't
            >>>>
            >>>>
            >>>know
            >>>
            >>>
            >>>>any names. But, they have tons of underwater
            >>>>transducers some focused some not. I beleive most
            >>>>
            >>>>
            >>>are
            >>>
            >>>
            >>>>in the MHz range.
            >>>>
            >>>>--- Jon Hylands <jon@...> wrote:
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>>On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
            >>>>><m.w.donnellan@...> wrote:
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>>I've done some work with land based sonar
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>avoidance behavior...but I've moved on to wetter
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>>climes. I'm wondering if anyone has used sonar on
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>underwater autonomous applications and
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>>if so, could recommend a good transducer (maybe
            >>>>>>
            >>>>>>
            >>>in
            >>>
            >>>
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>>
            >>>>>the 200 kHz range)?
            >>>>>
            >>>>>Mike,
            >>>>>
            >>>>>I got this word document from a guy a long time
            >>>>>
            >>>>>
            >>>ago
            >>>
            >>>
            >>>>>- he built a very
            >>>>>simple AUV using a cheap R/C sub, and put a simple
            >>>>>sonar on it, which he
            >>>>>describes within.
            >>>>>
            >>>>>http://www.huv.com/maus2.zip
            >>>>>
            >>>>>Let me know if this works for you, or what you
            >>>>>
            >>>>>
            >>>come
            >>>
            >>>
            >>>>>up with - I'm obviously
            >>>>>very interested in AUVs as well.
            >>>>>
            >>>>>Later,
            >>>>>Jon
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>--------------------------------------------------------------
            >>>
            >>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>> Jon Hylands Jon@...
            >>>>>http://www.huv.com/jon
            >>>>>
            >>>>> Project: Micro Seeker (Micro Autonomous
            >>>>>
            >>>>>
            >>>Underwater
            >>>
            >>>
            >>>>>Vehicle)
            >>>>> http://www.huv.com
            >>>>>
            >>>>>
            >>>>>Visit the SRS Website at
            >>>>>http://www.seattlerobotics.org
            >>>>>Yahoo! Groups Links
            >>>>>
            >>>>>
            >>>>> SeattleRobotics-unsubscribe@yahoogroups.com
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>>
            >>>>
            >>>>
            >>>>__________________________________
            >>>>Yahoo! FareChase: Search multiple travel sites in
            >>>>
            >>>>
            >>>one click.
            >>>
            >>>
            >>>>http://farechase.yahoo.com
            >>>>
            >>>>
            >>>>Visit the SRS Website at
            >>>>
            >>>>
            >>>http://www.seattlerobotics.org
            >>>
            >>>
            >>>>Yahoo! Groups Links
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>>
            >>>Visit the SRS Website at
            >>>http://www.seattlerobotics.org
            >>>Yahoo! Groups Links
            >>>
            >>>
            >>> SeattleRobotics-unsubscribe@yahoogroups.com
            >>>
            >>>
            >>>
            >>>
            >>>
            >>>
            >>>
            >>>
            >>
            >>
            >>
            >>__________________________________
            >>Yahoo! Mail - PC Magazine Editors' Choice 2005
            >>http://mail.yahoo.com
            >>
            >>
            >>Visit the SRS Website at http://www.seattlerobotics.org
            >>Yahoo! Groups Links
            >>
            >>
            >>
            >>
            >>
            >>
            >>
            >>
            >
            >
            >
            >
            >Visit the SRS Website at http://www.seattlerobotics.org
            >Yahoo! Groups Links
            >
            >
            >
            >
            >
            >
            >
            >
            >
          • Michael Donnellan
            Excellent info. What do you think of the idea of using frequency modulated (instead of pulse modulated) sonar signals?
            Message 5 of 22 , Nov 4, 2005
              Excellent info. What do you think of the idea of using frequency modulated
              (instead of pulse modulated) sonar signals?


              On 11/4/05 5:17 AM, "tbrenke@..." <tbrenke@...> wrote:

              > seawater common sonar freqs by distance
              > long range
              > 50Khz
              > 60Khz
              > 110Khz
              > 120Khz
              > 200Khz
              > 300Khz abt 700 feet max (in fresh water)
              > 455Khz
              >
              > you are looking for 60-110Khz sonar.
              > another factor with the freq is the size of the target you can see.
              > a 300Khz will see detals that a 110Khz and 60Khz will not.
              >
              >
              > Michael Donnellan wrote:
              >
              >> Higher frequencies may work well for close range avoidance behavior, but I
              >> need something for much greater depth and distance (100 - 500 meters). Also,
              >> some frequencies that work in air or fresh water are seriously disrupted in
              >> sea water.
              >>
              >>
              >>
              >> On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
              >>
              >>
              >>
              >>> That sound about right. NDT transducers are made to
              >>> find flaws in manufactured parts. The frequency sets
              >>> the size of flaw that will reflect sound back.
              >>>
              >>> --- "tbrenke@..." <tbrenke@...> wrote:
              >>>
              >>>
              >>>
              >>>> Mhz will not go far in water.
              >>>> 1.2Mhz is good for only about 20'
              >>>> (at best)
              >>>>
              >>>> Tony Brenke
              >>>> WESMAR
              >>>> (sonar maker)
              >>>>
              >>>>
              >>>>
              >>>>
              >>>> Charles Holzschuh wrote:
              >>>>
              >>>>
              >>>>
              >>>>> Try a non-destructive testing supplier. I don't
              >>>>>
              >>>>>
              >>>> know
              >>>>
              >>>>
              >>>>> any names. But, they have tons of underwater
              >>>>> transducers some focused some not. I beleive most
              >>>>>
              >>>>>
              >>>> are
              >>>>
              >>>>
              >>>>> in the MHz range.
              >>>>>
              >>>>> --- Jon Hylands <jon@...> wrote:
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>> On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
              >>>>>> <m.w.donnellan@...> wrote:
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>> I've done some work with land based sonar
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>> avoidance behavior...but I've moved on to wetter
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>> climes. I'm wondering if anyone has used sonar on
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>> underwater autonomous applications and
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>> if so, could recommend a good transducer (maybe
              >>>>>>>
              >>>>>>>
              >>>> in
              >>>>
              >>>>
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>>>
              >>>>>> the 200 kHz range)?
              >>>>>>
              >>>>>> Mike,
              >>>>>>
              >>>>>> I got this word document from a guy a long time
              >>>>>>
              >>>>>>
              >>>> ago
              >>>>
              >>>>
              >>>>>> - he built a very
              >>>>>> simple AUV using a cheap R/C sub, and put a simple
              >>>>>> sonar on it, which he
              >>>>>> describes within.
              >>>>>>
              >>>>>> http://www.huv.com/maus2.zip
              >>>>>>
              >>>>>> Let me know if this works for you, or what you
              >>>>>>
              >>>>>>
              >>>> come
              >>>>
              >>>>
              >>>>>> up with - I'm obviously
              >>>>>> very interested in AUVs as well.
              >>>>>>
              >>>>>> Later,
              >>>>>> Jon
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>> --------------------------------------------------------------
              >>>>
              >>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>> Jon Hylands Jon@...
              >>>>>> http://www.huv.com/jon
              >>>>>>
              >>>>>> Project: Micro Seeker (Micro Autonomous
              >>>>>>
              >>>>>>
              >>>> Underwater
              >>>>
              >>>>
              >>>>>> Vehicle)
              >>>>>> http://www.huv.com
              >>>>>>
              >>>>>>
              >>>>>> Visit the SRS Website at
              >>>>>> http://www.seattlerobotics.org
              >>>>>> Yahoo! Groups Links
              >>>>>>
              >>>>>>
              >>>>>> SeattleRobotics-unsubscribe@yahoogroups.com
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>>
              >>>>>
              >>>>>
              >>>>> __________________________________
              >>>>> Yahoo! FareChase: Search multiple travel sites in
              >>>>>
              >>>>>
              >>>> one click.
              >>>>
              >>>>
              >>>>> http://farechase.yahoo.com
              >>>>>
              >>>>>
              >>>>> Visit the SRS Website at
              >>>>>
              >>>>>
              >>>> http://www.seattlerobotics.org
              >>>>
              >>>>
              >>>>> Yahoo! Groups Links
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>>>
              >>>> Visit the SRS Website at
              >>>> http://www.seattlerobotics.org
              >>>> Yahoo! Groups Links
              >>>>
              >>>>
              >>>> SeattleRobotics-unsubscribe@yahoogroups.com
              >>>>
              >>>>
              >>>>
              >>>>
              >>>>
              >>>>
              >>>>
              >>>>
              >>>
              >>>
              >>>
              >>> __________________________________
              >>> Yahoo! Mail - PC Magazine Editors' Choice 2005
              >>> http://mail.yahoo.com
              >>>
              >>>
              >>> Visit the SRS Website at http://www.seattlerobotics.org
              >>> Yahoo! Groups Links
              >>>
              >>>
              >>>
              >>>
              >>>
              >>>
              >>>
              >>>
              >>
              >>
              >>
              >>
              >> Visit the SRS Website at http://www.seattlerobotics.org
              >> Yahoo! Groups Links
              >>
              >>
              >>
              >>
              >>
              >>
              >>
              >>
              >>
              >
              >
              > Visit the SRS Website at http://www.seattlerobotics.org
              > Yahoo! Groups Links
              >
              >
              >
              >
              >
              >
            • tbrenke@verizon.net
              the way our searchlight sonar work is like this. TX a pulse of a set length for a set range IE 25 is a pulse of 80mS listen for the time it takes sound to
              Message 6 of 22 , Nov 5, 2005
                the way our searchlight sonar work is like this.
                TX a pulse of a set length for a set range
                IE 25' is a pulse of 80mS
                listen for the time it takes sound to travel in water 50' (round trip)
                take samples over that time to get the magnitude of the return.
                plot that to the screen.
                this uses a narrow freq filter to return only the freq you sent out.

                our sidescan sonar work is like this.
                TX a pulse of a set length for a set range
                IE 25' is a pulse of 80mS
                listen for the time it takes sound to travel in water 50' (round trip)
                take samples over that time to get the magnitude of the return.
                plot that to the screen.
                this uses a wide freq filter to return details of the object being viewed

                our "catch sensors" in the trawl net are in the 27kHz range.
                they use a low power TX and send two different freq for "triggered" and
                "active"
                they can still be heard a mile away.

                the freq and pulse length are optimized for what you are trying to do.
                long distance searchlight for a boat can easily use a 110kHz freq and an
                average pulse of 100-200mS

                is this only for a downsounder type os setup?



                Michael Donnellan wrote:

                >Excellent info. What do you think of the idea of using frequency modulated
                >(instead of pulse modulated) sonar signals?
                >
                >
                >On 11/4/05 5:17 AM, "tbrenke@..." <tbrenke@...> wrote:
                >
                >
                >
                >>seawater common sonar freqs by distance
                >>long range
                >>50Khz
                >>60Khz
                >>110Khz
                >>120Khz
                >>200Khz
                >>300Khz abt 700 feet max (in fresh water)
                >>455Khz
                >>
                >>you are looking for 60-110Khz sonar.
                >>another factor with the freq is the size of the target you can see.
                >>a 300Khz will see detals that a 110Khz and 60Khz will not.
                >>
                >>
                >>Michael Donnellan wrote:
                >>
                >>
                >>
                >>>Higher frequencies may work well for close range avoidance behavior, but I
                >>>need something for much greater depth and distance (100 - 500 meters). Also,
                >>>some frequencies that work in air or fresh water are seriously disrupted in
                >>>sea water.
                >>>
                >>>
                >>>
                >>>On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>>That sound about right. NDT transducers are made to
                >>>>find flaws in manufactured parts. The frequency sets
                >>>>the size of flaw that will reflect sound back.
                >>>>
                >>>>--- "tbrenke@..." <tbrenke@...> wrote:
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>>Mhz will not go far in water.
                >>>>>1.2Mhz is good for only about 20'
                >>>>>(at best)
                >>>>>
                >>>>>Tony Brenke
                >>>>>WESMAR
                >>>>>(sonar maker)
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>Charles Holzschuh wrote:
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>Try a non-destructive testing supplier. I don't
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>know
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>any names. But, they have tons of underwater
                >>>>>>transducers some focused some not. I beleive most
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>are
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>in the MHz range.
                >>>>>>
                >>>>>>--- Jon Hylands <jon@...> wrote:
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>>On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
                >>>>>>><m.w.donnellan@...> wrote:
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>>I've done some work with land based sonar
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>avoidance behavior...but I've moved on to wetter
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>>climes. I'm wondering if anyone has used sonar on
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>underwater autonomous applications and
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>>if so, could recommend a good transducer (maybe
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>in
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>>
                >>>>>>>the 200 kHz range)?
                >>>>>>>
                >>>>>>>Mike,
                >>>>>>>
                >>>>>>>I got this word document from a guy a long time
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>ago
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>>- he built a very
                >>>>>>>simple AUV using a cheap R/C sub, and put a simple
                >>>>>>>sonar on it, which he
                >>>>>>>describes within.
                >>>>>>>
                >>>>>>>http://www.huv.com/maus2.zip
                >>>>>>>
                >>>>>>>Let me know if this works for you, or what you
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>come
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>>up with - I'm obviously
                >>>>>>>very interested in AUVs as well.
                >>>>>>>
                >>>>>>>Later,
                >>>>>>>Jon
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>--------------------------------------------------------------
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>> Jon Hylands Jon@...
                >>>>>>>http://www.huv.com/jon
                >>>>>>>
                >>>>>>>Project: Micro Seeker (Micro Autonomous
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>Underwater
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>>Vehicle)
                >>>>>>> http://www.huv.com
                >>>>>>>
                >>>>>>>
                >>>>>>>Visit the SRS Website at
                >>>>>>>http://www.seattlerobotics.org
                >>>>>>>Yahoo! Groups Links
                >>>>>>>
                >>>>>>>
                >>>>>>> SeattleRobotics-unsubscribe@yahoogroups.com
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>>
                >>>>>>__________________________________
                >>>>>>Yahoo! FareChase: Search multiple travel sites in
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>one click.
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>http://farechase.yahoo.com
                >>>>>>
                >>>>>>
                >>>>>>Visit the SRS Website at
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>http://www.seattlerobotics.org
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>>Yahoo! Groups Links
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>>
                >>>>>Visit the SRS Website at
                >>>>>http://www.seattlerobotics.org
                >>>>>Yahoo! Groups Links
                >>>>>
                >>>>>
                >>>>> SeattleRobotics-unsubscribe@yahoogroups.com
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>>
                >>>>
                >>>>__________________________________
                >>>>Yahoo! Mail - PC Magazine Editors' Choice 2005
                >>>>http://mail.yahoo.com
                >>>>
                >>>>
                >>>>Visit the SRS Website at http://www.seattlerobotics.org
                >>>>Yahoo! Groups Links
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>>
                >>>
                >>>
                >>>Visit the SRS Website at http://www.seattlerobotics.org
                >>>Yahoo! Groups Links
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>>
                >>Visit the SRS Website at http://www.seattlerobotics.org
                >>Yahoo! Groups Links
                >>
                >>
                >>
                >>
                >>
                >>
                >>
                >>
                >
                >
                >
                >
                >Visit the SRS Website at http://www.seattlerobotics.org
                >Yahoo! Groups Links
                >
                >
                >
                >
                >
                >
                >
                >
                >
              • tbrenke@verizon.net
                oh, if you mean sending a sonar pulse of say 100mS at a varable freq, then you would be hard pressed to get the needed power into the water. each transducer
                Message 7 of 22 , Nov 5, 2005
                  oh,
                  if you mean sending a sonar pulse of say 100mS at a varable freq, then
                  you would be hard pressed to get the needed power into the water.
                  each transducer has a optomal freq that it will use.
                  sending a wide range would require more then one transducer array.
                  size will very quickly become an issue.



                  Michael Donnellan wrote:

                  >Excellent info. What do you think of the idea of using frequency modulated
                  >(instead of pulse modulated) sonar signals?
                  >
                  >
                  >On 11/4/05 5:17 AM, "tbrenke@..." <tbrenke@...> wrote:
                  >
                  >
                  >
                  >>seawater common sonar freqs by distance
                  >>long range
                  >>50Khz
                  >>60Khz
                  >>110Khz
                  >>120Khz
                  >>200Khz
                  >>300Khz abt 700 feet max (in fresh water)
                  >>455Khz
                  >>
                  >>you are looking for 60-110Khz sonar.
                  >>another factor with the freq is the size of the target you can see.
                  >>a 300Khz will see detals that a 110Khz and 60Khz will not.
                  >>
                  >>
                  >>Michael Donnellan wrote:
                  >>
                  >>
                  >>
                  >>>Higher frequencies may work well for close range avoidance behavior, but I
                  >>>need something for much greater depth and distance (100 - 500 meters). Also,
                  >>>some frequencies that work in air or fresh water are seriously disrupted in
                  >>>sea water.
                  >>>
                  >>>
                  >>>
                  >>>On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>>That sound about right. NDT transducers are made to
                  >>>>find flaws in manufactured parts. The frequency sets
                  >>>>the size of flaw that will reflect sound back.
                  >>>>
                  >>>>--- "tbrenke@..." <tbrenke@...> wrote:
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>>Mhz will not go far in water.
                  >>>>>1.2Mhz is good for only about 20'
                  >>>>>(at best)
                  >>>>>
                  >>>>>Tony Brenke
                  >>>>>WESMAR
                  >>>>>(sonar maker)
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>Charles Holzschuh wrote:
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>Try a non-destructive testing supplier. I don't
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>know
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>any names. But, they have tons of underwater
                  >>>>>>transducers some focused some not. I beleive most
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>are
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>in the MHz range.
                  >>>>>>
                  >>>>>>--- Jon Hylands <jon@...> wrote:
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>>On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
                  >>>>>>><m.w.donnellan@...> wrote:
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>>I've done some work with land based sonar
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>avoidance behavior...but I've moved on to wetter
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>>climes. I'm wondering if anyone has used sonar on
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>underwater autonomous applications and
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>>if so, could recommend a good transducer (maybe
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>in
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>>
                  >>>>>>>the 200 kHz range)?
                  >>>>>>>
                  >>>>>>>Mike,
                  >>>>>>>
                  >>>>>>>I got this word document from a guy a long time
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>ago
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>>- he built a very
                  >>>>>>>simple AUV using a cheap R/C sub, and put a simple
                  >>>>>>>sonar on it, which he
                  >>>>>>>describes within.
                  >>>>>>>
                  >>>>>>>http://www.huv.com/maus2.zip
                  >>>>>>>
                  >>>>>>>Let me know if this works for you, or what you
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>come
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>>up with - I'm obviously
                  >>>>>>>very interested in AUVs as well.
                  >>>>>>>
                  >>>>>>>Later,
                  >>>>>>>Jon
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>--------------------------------------------------------------
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>> Jon Hylands Jon@...
                  >>>>>>>http://www.huv.com/jon
                  >>>>>>>
                  >>>>>>>Project: Micro Seeker (Micro Autonomous
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>Underwater
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>>Vehicle)
                  >>>>>>> http://www.huv.com
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>Visit the SRS Website at
                  >>>>>>>http://www.seattlerobotics.org
                  >>>>>>>Yahoo! Groups Links
                  >>>>>>>
                  >>>>>>>
                  >>>>>>> SeattleRobotics-unsubscribe@yahoogroups.com
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>>
                  >>>>>>__________________________________
                  >>>>>>Yahoo! FareChase: Search multiple travel sites in
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>one click.
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>http://farechase.yahoo.com
                  >>>>>>
                  >>>>>>
                  >>>>>>Visit the SRS Website at
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>http://www.seattlerobotics.org
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>>Yahoo! Groups Links
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>>
                  >>>>>Visit the SRS Website at
                  >>>>>http://www.seattlerobotics.org
                  >>>>>Yahoo! Groups Links
                  >>>>>
                  >>>>>
                  >>>>> SeattleRobotics-unsubscribe@yahoogroups.com
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>
                  >>>>__________________________________
                  >>>>Yahoo! Mail - PC Magazine Editors' Choice 2005
                  >>>>http://mail.yahoo.com
                  >>>>
                  >>>>
                  >>>>Visit the SRS Website at http://www.seattlerobotics.org
                  >>>>Yahoo! Groups Links
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>>
                  >>>
                  >>>
                  >>>Visit the SRS Website at http://www.seattlerobotics.org
                  >>>Yahoo! Groups Links
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>Visit the SRS Website at http://www.seattlerobotics.org
                  >>Yahoo! Groups Links
                  >>
                  >>
                  >>
                  >>
                  >>
                  >>
                  >>
                  >>
                  >
                  >
                  >
                  >
                  >Visit the SRS Website at http://www.seattlerobotics.org
                  >Yahoo! Groups Links
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                  >
                • Michael Donnellan
                  Basically this rig is for an autonomous robotic mapping submarine. They would travel in schools to create a wide viewing path and be able gain better
                  Message 8 of 22 , Nov 5, 2005
                    Basically this rig is for an autonomous robotic mapping submarine. They
                    would travel in "schools" to create a wide viewing path and be able gain
                    better resolution due to multiple beam angles. So while there is a need for
                    moderate sonar ranging on the horizontal plane (short distance) the primary
                    use is for vertical depth perception and identification of bottom substrate
                    (but that's an entirely different discussion).

                    Mike

                    PS This is great info....thank you.


                    On 11/5/05 10:08 AM, "tbrenke@..." <tbrenke@...> wrote:

                    > the way our searchlight sonar work is like this.
                    > TX a pulse of a set length for a set range
                    > IE 25' is a pulse of 80mS
                    > listen for the time it takes sound to travel in water 50' (round trip)
                    > take samples over that time to get the magnitude of the return.
                    > plot that to the screen.
                    > this uses a narrow freq filter to return only the freq you sent out.
                    >
                    > our sidescan sonar work is like this.
                    > TX a pulse of a set length for a set range
                    > IE 25' is a pulse of 80mS
                    > listen for the time it takes sound to travel in water 50' (round trip)
                    > take samples over that time to get the magnitude of the return.
                    > plot that to the screen.
                    > this uses a wide freq filter to return details of the object being viewed
                    >
                    > our "catch sensors" in the trawl net are in the 27kHz range.
                    > they use a low power TX and send two different freq for "triggered" and
                    > "active"
                    > they can still be heard a mile away.
                    >
                    > the freq and pulse length are optimized for what you are trying to do.
                    > long distance searchlight for a boat can easily use a 110kHz freq and an
                    > average pulse of 100-200mS
                    >
                    > is this only for a downsounder type os setup?
                    >
                    >
                    >
                    > Michael Donnellan wrote:
                    >
                    >> Excellent info. What do you think of the idea of using frequency modulated
                    >> (instead of pulse modulated) sonar signals?
                    >>
                    >>
                    >> On 11/4/05 5:17 AM, "tbrenke@..." <tbrenke@...> wrote:
                    >>
                    >>
                    >>
                    >>> seawater common sonar freqs by distance
                    >>> long range
                    >>> 50Khz
                    >>> 60Khz
                    >>> 110Khz
                    >>> 120Khz
                    >>> 200Khz
                    >>> 300Khz abt 700 feet max (in fresh water)
                    >>> 455Khz
                    >>>
                    >>> you are looking for 60-110Khz sonar.
                    >>> another factor with the freq is the size of the target you can see.
                    >>> a 300Khz will see detals that a 110Khz and 60Khz will not.
                    >>>
                    >>>
                    >>> Michael Donnellan wrote:
                    >>>
                    >>>
                    >>>
                    >>>> Higher frequencies may work well for close range avoidance behavior, but I
                    >>>> need something for much greater depth and distance (100 - 500 meters).
                    >>>> Also,
                    >>>> some frequencies that work in air or fresh water are seriously disrupted in
                    >>>> sea water.
                    >>>>
                    >>>>
                    >>>>
                    >>>> On 11/3/05 6:06 PM, "Charles Holzschuh" <xolzscxux@...> wrote:
                    >>>>
                    >>>>
                    >>>>
                    >>>>
                    >>>>
                    >>>>> That sound about right. NDT transducers are made to
                    >>>>> find flaws in manufactured parts. The frequency sets
                    >>>>> the size of flaw that will reflect sound back.
                    >>>>>
                    >>>>> --- "tbrenke@..." <tbrenke@...> wrote:
                    >>>>>
                    >>>>>
                    >>>>>
                    >>>>>
                    >>>>>
                    >>>>>> Mhz will not go far in water.
                    >>>>>> 1.2Mhz is good for only about 20'
                    >>>>>> (at best)
                    >>>>>>
                    >>>>>> Tony Brenke
                    >>>>>> WESMAR
                    >>>>>> (sonar maker)
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>> Charles Holzschuh wrote:
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>> Try a non-destructive testing supplier. I don't
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>> know
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>> any names. But, they have tons of underwater
                    >>>>>>> transducers some focused some not. I beleive most
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>> are
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>> in the MHz range.
                    >>>>>>>
                    >>>>>>> --- Jon Hylands <jon@...> wrote:
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>> On Sat, 29 Oct 2005 01:40:31 -0000, "mwdonnellan"
                    >>>>>>>> <m.w.donnellan@...> wrote:
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>> I've done some work with land based sonar
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>> avoidance behavior...but I've moved on to wetter
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>> climes. I'm wondering if anyone has used sonar on
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>> underwater autonomous applications and
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>> if so, could recommend a good transducer (maybe
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>> in
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>>>
                    >>>>>>>> the 200 kHz range)?
                    >>>>>>>>
                    >>>>>>>> Mike,
                    >>>>>>>>
                    >>>>>>>> I got this word document from a guy a long time
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>> ago
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>>> - he built a very
                    >>>>>>>> simple AUV using a cheap R/C sub, and put a simple
                    >>>>>>>> sonar on it, which he
                    >>>>>>>> describes within.
                    >>>>>>>>
                    >>>>>>>> http://www.huv.com/maus2.zip
                    >>>>>>>>
                    >>>>>>>> Let me know if this works for you, or what you
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>> come
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>>> up with - I'm obviously
                    >>>>>>>> very interested in AUVs as well.
                    >>>>>>>>
                    >>>>>>>> Later,
                    >>>>>>>> Jon
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>>>>
                    >>>>>> --------------------------------------------------------------
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>> Jon Hylands Jon@...
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                    >>>>>>>>
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                    >>>>>>>> Visit the SRS Website at
                    >>>>>>>> http://www.seattlerobotics.org
                    >>>>>>>> Yahoo! Groups Links
                    >>>>>>>>
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                    >>>>>>
                    >>>>>>> Yahoo! Groups Links
                    >>>>>>>
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                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
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                    >>>>>>>
                    >>>>>>>
                    >>>>>>>
                    >>>>>> Visit the SRS Website at
                    >>>>>> http://www.seattlerobotics.org
                    >>>>>> Yahoo! Groups Links
                    >>>>>>
                    >>>>>>
                    >>>>>> SeattleRobotics-unsubscribe@yahoogroups.com
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                    >>>>>
                    >>>>> __________________________________
                    >>>>> Yahoo! Mail - PC Magazine Editors' Choice 2005
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                    >>>> Yahoo! Groups Links
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                    >>> Yahoo! Groups Links
                    >>>
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                    >>
                    >>
                    >>
                    >>
                    >> Visit the SRS Website at http://www.seattlerobotics.org
                    >> Yahoo! Groups Links
                    >>
                    >>
                    >>
                    >>
                    >>
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                    >>
                    >>
                    >>
                    >
                    >
                    > Visit the SRS Website at http://www.seattlerobotics.org
                    > Yahoo! Groups Links
                    >
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                  • Chuck Harrison
                    the primary use is for vertical depth perception I don t have any experience with underwater sonar but this sounds like it could be analagous to radar
                    Message 9 of 22 , Nov 5, 2005
                      " the primary use is for vertical depth perception "

                      I don't have any experience with underwater sonar but this sounds
                      like it could be analagous to radar altimeters used in aircraft.

                      I think someone asked about swept-frequency or "chirped" sonar.
                      Again, I don't know about sonar apps but this is a very simple
                      and effective technique in radar altimetry. You send out a
                      long chirp -- long enough so that the return signal overlaps
                      extensively with the transmit signal. Beat the return signal
                      against the transmit signal in a mixer and you get a beat
                      frequency which is proportional to distance. The chirp needs to
                      be linear with time.

                      Lotsa luck!
                      Chuck

                      Michael Donnellan wrote:
                      >
                      > Basically this rig is for an autonomous robotic mapping submarine. They
                      > would travel in "schools" to create a wide viewing path and be able gain
                      > better resolution due to multiple beam angles. So while there is a need for
                      > moderate sonar ranging on the horizontal plane (short distance) the primary
                      > use is for vertical depth perception and identification of bottom substrate
                      > (but that's an entirely different discussion).
                      >
                      > Mike
                    • Michael Donnellan
                      Chuck, this is interesting. Do you have any reference sites or schematics regarding the construction of the mixer? Mike
                      Message 10 of 22 , Nov 5, 2005
                        Chuck, this is interesting. Do you have any reference sites or schematics
                        regarding the construction of the mixer?
                        Mike


                        On 11/5/05 1:25 PM, "Chuck Harrison" <cfharr@...> wrote:

                        > " the primary use is for vertical depth perception "
                        >
                        > I don't have any experience with underwater sonar but this sounds
                        > like it could be analagous to radar altimeters used in aircraft.
                        >
                        > I think someone asked about swept-frequency or "chirped" sonar.
                        > Again, I don't know about sonar apps but this is a very simple
                        > and effective technique in radar altimetry. You send out a
                        > long chirp -- long enough so that the return signal overlaps
                        > extensively with the transmit signal. Beat the return signal
                        > against the transmit signal in a mixer and you get a beat
                        > frequency which is proportional to distance. The chirp needs to
                        > be linear with time.
                        >
                        > Lotsa luck!
                        > Chuck
                        >
                        > Michael Donnellan wrote:
                        >>
                        >> Basically this rig is for an autonomous robotic mapping submarine. They
                        >> would travel in "schools" to create a wide viewing path and be able gain
                        >> better resolution due to multiple beam angles. So while there is a need for
                        >> moderate sonar ranging on the horizontal plane (short distance) the primary
                        >> use is for vertical depth perception and identification of bottom substrate
                        >> (but that's an entirely different discussion).
                        >>
                        >> Mike
                        >
                        >
                        > Visit the SRS Website at http://www.seattlerobotics.org
                        > Yahoo! Groups Links
                        >
                        >
                        >
                        >
                        >
                        >
                      • Tony Mactutis
                        Would a chirp also be more useful in that it could be used in conjunction with signal processing techniques (eg. autocorrelation) to improve the
                        Message 11 of 22 , Nov 5, 2005
                          Would a chirp also be more useful in that it could be used in
                          conjunction with signal processing techniques (eg. autocorrelation) to
                          improve the signal-to-noise?

                          Chuck Harrison wrote:

                          >I think someone asked about swept-frequency or "chirped" sonar.
                          >Again, I don't know about sonar apps but this is a very simple
                          >and effective technique in radar altimetry. You send out a
                          >long chirp -- long enough so that the return signal overlaps
                          >extensively with the transmit signal. Beat the return signal
                          >against the transmit signal in a mixer and you get a beat
                          >frequency which is proportional to distance. The chirp needs to
                          >be linear with time.
                          >
                          >Lotsa luck!
                          > Chuck
                          >
                          >
                          >
                        • twcarroll@aol.com
                          Chuck, If the frequency changes and you result in a harmonic or beat frequency when you mix the outgoing signal and the incoming signal, you have experienced
                          Message 12 of 22 , Nov 5, 2005
                            Chuck,
                            If the frequency changes and you result in a harmonic or beat frequency
                            when you mix the outgoing signal and the incoming signal, you have
                            experienced the Doppler effect which is a function of the speed between
                            the transmitter and the target object,- not distance. If the returning
                            signal is higher than the sent signal, the object is coming towards the
                            transmitter, and vice/versa for a lower frequency (like the "red shift"
                            in measuring speed of receding stars). You measure a time domain
                            between the out going signal and the return signal. The longer the time
                            the further away the target is. This is the way old PPI radar screens
                            (CRTs) worked.
                            Tom Carroll

                            Chuck Harrison wrote:
                            >I think someone asked about swept-frequency or "chirped" sonar.
                            >Again, I don't know about sonar apps but this is a very simple
                            >and effective technique in radar altimetry. You send out a
                            >long chirp -- long enough so that the return signal overlaps
                            >extensively with the transmit signal. Beat the return signal
                            >against the transmit signal in a mixer and you get a beat
                            >frequency which is proportional to distance. The chirp needs to
                            >be linear with time.
                            >
                            >Lotsa luck!
                            > Chuck
                            >
                            >
                            >



                            Visit the SRS Website at http://www.seattlerobotics.org
                            Yahoo! Groups Links
                          • Chuck Harrison
                            Wait, we re *both* right. Doppler radar for velocity measurement (in its ordinary form) *doesn t* use an FM sweep (chirp) -- it works just great with pulsed
                            Message 13 of 22 , Nov 5, 2005
                              Wait, we're *both* right.

                              Doppler radar for velocity measurement (in its ordinary form)
                              *doesn't* use an FM sweep (chirp) -- it works just great with
                              pulsed CW. And the same Doppler principle surely works with
                              ultrasound, it's the basis of the common ultrasonic motion detector
                              used in security alarm systems. Those are straight CW transmitters,
                              no pulsing at all.

                              On the other hand, the FM radar altimeters give a beat signal even
                              when there is *no* relative motion. That's because the return signal
                              is effectively a delayed version of the TX, and has a frequency
                              difference equal to (FM sweep rate) x (echo delay).

                              FM radar altimeters *do* also respond to rate-of-rise or rate-of-
                              descent, according to the Doppler effect as mentioned. By using
                              triangle-wave FM modulation and averaging, the Doppler effect
                              can be cancelled. Google "radar altimeter" or try:
                              http://www.vectorsite.net/ttradar2.html#m5

                              I have heard that sonar transducers are notoriously narrow-band,
                              so FM sweep may not be very viable.

                              Peace & waves,
                              Chuck

                              twcarroll@... wrote:
                              >
                              > Chuck,
                              > If the frequency changes and you result in a harmonic or beat frequency
                              > when you mix the outgoing signal and the incoming signal, you have
                              > experienced the Doppler effect which is a function of the speed between
                              > the transmitter and the target object,- not distance. If the returning
                              > signal is higher than the sent signal, the object is coming towards the
                              > transmitter, and vice/versa for a lower frequency (like the "red shift"
                              > in measuring speed of receding stars). You measure a time domain
                              > between the out going signal and the return signal. The longer the time
                              > the further away the target is. This is the way old PPI radar screens
                              > (CRTs) worked.
                              > Tom Carroll
                              >
                              > Chuck Harrison wrote:
                              > >I think someone asked about swept-frequency or "chirped" sonar.
                              > >Again, I don't know about sonar apps but this is a very simple
                              > >and effective technique in radar altimetry. You send out a
                              > >long chirp -- long enough so that the return signal overlaps
                              > >extensively with the transmit signal. Beat the return signal
                              > >against the transmit signal in a mixer and you get a beat
                              > >frequency which is proportional to distance. The chirp needs to
                              > >be linear with time.
                              > >
                              > >Lotsa luck!
                              > > Chuck
                              > >
                              > >
                              > >
                              >
                              > Visit the SRS Website at http://www.seattlerobotics.org
                              > Yahoo! Groups Links
                              >
                              > Visit the SRS Website at http://www.seattlerobotics.org
                              > Yahoo! Groups Links
                              >
                              >
                              >
                              >
                            • tbrenke@verizon.net
                              the way I would do this is with a single side scan transducer in the 300kHz range. pointed down it will give a beam angle of 1.5 degrees in fore/aft and about
                              Message 14 of 22 , Nov 5, 2005
                                the way I would do this is with a single side scan transducer in the
                                300kHz range.
                                pointed down it will give a beam angle of 1.5 degrees in fore/aft and
                                about 90 degrees to each side. how far you will see to the side will be
                                a function of how far away from the bottom your sub is.
                                subs in packs would take care of the details.
                                for best resolution each sub should travel at the same over-the-ground
                                speed.

                                there are some issues that need to be cured.
                                the location of each sub needs to be known at all times to give you are
                                accurate picture of overlapping tracks.
                                this would require high def gps because standard gps is good for +/- 15'
                                I am not sure if that signal is available under the water surface.

                                then there is the case of data.
                                saving that much data and the location of of each TX/RX scan will
                                require a large flash section.

                                I have ideas to cure this but that has its own set of complications.

                                if you want to take this off the list,
                                my email address is tbrenke at verizon dot net





                                Michael Donnellan wrote:

                                >Basically this rig is for an autonomous robotic mapping submarine. They
                                >would travel in "schools" to create a wide viewing path and be able gain
                                >better resolution due to multiple beam angles. So while there is a need for
                                >moderate sonar ranging on the horizontal plane (short distance) the primary
                                >use is for vertical depth perception and identification of bottom substrate
                                >(but that's an entirely different discussion).
                                >
                                >Mike
                                >
                                >PS This is great info....thank you.
                                >
                                >
                                >
                                >
                              • tbrenke@verizon.net
                                hmmm, from the ammount of interst, I would keep this on the list. fasanating conversations.
                                Message 15 of 22 , Nov 5, 2005
                                  hmmm,
                                  from the ammount of interst, I would keep this on the list.

                                  fasanating conversations.
                                • tbrenke@verizon.net
                                  an example of the sidescan method of sampling can be seen here. http://oceanexplorer.noaa.gov/explorations/02hudson/background/mapping/mapping.html more
                                  Message 16 of 22 , Nov 5, 2005
                                    an example of the sidescan method of sampling can be seen here.
                                    http://oceanexplorer.noaa.gov/explorations/02hudson/background/mapping/mapping.html
                                    more efective then the down sounds style.
                                  • Michael Donnellan
                                    Well....accurate position determination is a major stumbling block (if we put our heads together on this it s probably worthy of DARPA funding :) Since GPS
                                    Message 17 of 22 , Nov 5, 2005
                                      Well....accurate position determination is a major stumbling block (if we
                                      put our heads together on this it's probably worthy of DARPA funding :)

                                      Since GPS underwater is highly sketchy to my knowledge, my thought is to
                                      navigate via relative positioning to each other. Like a fighter plane
                                      sortie, these subs would travel in a triangular formation with one leader.
                                      Therefore, the others would position themselves relative to the position of
                                      the alpha sub.

                                      I had originally toyed with the idea of geomagnetic positioning....but that
                                      is WAY beyond my pea brain, and from skimming DARPA grant proposals...way
                                      beyond a lot of other brains far superior to mine.

                                      The mapping scenario is an interesting one. The concept is this...say we
                                      were to drop our subs into an ocean of unknown dimension on another planet.
                                      The subs would have to travel by navigation in relation to each other's
                                      positions (since we can't be sure there is any magnetic pole...and gps is
                                      non existent). Then some kind of algorithm needs to be created to basically
                                      cover the greatest surface area (mapping area) with the least consumption of
                                      power. At this point in my thought process, battery recharge would have to
                                      be via solar panels during surfacing (also when telemetry of map data takes
                                      place). I have had a discussion about generating power through temperature
                                      differentials within the water column-=however, this is still pie in the sky
                                      currently.

                                      Thoughts on the issue?


                                      On 11/5/05 8:54 PM, "tbrenke@..." <tbrenke@...> wrote:

                                      > the way I would do this is with a single side scan transducer in the
                                      > 300kHz range.
                                      > pointed down it will give a beam angle of 1.5 degrees in fore/aft and
                                      > about 90 degrees to each side. how far you will see to the side will be
                                      > a function of how far away from the bottom your sub is.
                                      > subs in packs would take care of the details.
                                      > for best resolution each sub should travel at the same over-the-ground
                                      > speed.
                                      >
                                      > there are some issues that need to be cured.
                                      > the location of each sub needs to be known at all times to give you are
                                      > accurate picture of overlapping tracks.
                                      > this would require high def gps because standard gps is good for +/- 15'
                                      > I am not sure if that signal is available under the water surface.
                                      >
                                      > then there is the case of data.
                                      > saving that much data and the location of of each TX/RX scan will
                                      > require a large flash section.
                                      >
                                      > I have ideas to cure this but that has its own set of complications.
                                      >
                                      > if you want to take this off the list,
                                      > my email address is tbrenke at verizon dot net
                                      >
                                      >
                                      >
                                      >
                                      >
                                      > Michael Donnellan wrote:
                                      >
                                      >> Basically this rig is for an autonomous robotic mapping submarine. They
                                      >> would travel in "schools" to create a wide viewing path and be able gain
                                      >> better resolution due to multiple beam angles. So while there is a need for
                                      >> moderate sonar ranging on the horizontal plane (short distance) the primary
                                      >> use is for vertical depth perception and identification of bottom substrate
                                      >> (but that's an entirely different discussion).
                                      >>
                                      >> Mike
                                      >>
                                      >> PS This is great info....thank you.
                                      >>
                                      >>
                                      >>
                                      >>
                                      >
                                      >
                                      > Visit the SRS Website at http://www.seattlerobotics.org
                                      > Yahoo! Groups Links
                                      >
                                      >
                                      >
                                      >
                                      >
                                      >
                                      >
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